Deep genome skimming reveals the hybrid origin of Pseudosasa gracilis (Poaceae: Bambusoideae)

Pseudosasa gracilis(Poaceae:Bambusoideae)is a temperate woody bamboo species endemic to Southcentral China with a narrow distribution.Previous phylogenetic studies revealed an unexpected,isolated phylogenetic position of Ps.gracilis.Here we conducted phylogenomic analysis by sampling populations of Ps.gracilis and its sympatric species Ps.nanunica and Sinosasa polytricha reflecting different genomic signals,by deep genome skimming.Integrating molecular evidence from chloroplast genes and genome-wide SNPs,we deciphered the phylogenetic relationships of Ps.gracilis.Both plastid and nuclear data indicate that Ps.gracilis is more closely related to Sinosasa,which is discordant with the taxonomic treatment.To further explore this molecular-morphological conflict,we screened 411“perfect-copy”syntenic genes to reconstruct phylogenies using both the concatenation and coalescent methods.We observed extensive discordance between gene trees and the putative species tree.A significant hybridization event was detected based on 411 genes from the D subgenome,showing Ps.gracilis was a hybrid descendant between Sinosasa longiligulata and Ps.nanunica,with 63.56%and 36.44%inheritance probabilities of each parent.Moreover,introgression events were detected in the C subgenome between Ps.gracilis and S.polytricha in the same distribution region.Our findings suggest that sympatric hybridization and introgression play a crucial role in the origin of Ps.gracilis.By providing an empirical example of bamboo of hybrid origin using comprehensive analyses based on genomic data from different inheritance systems and morphological characters,our study represents a step forward in understanding of reticulate evolution of bamboos.

Effects of light quality on growth rates and pigments of Chaetoceros gracilis(Bacillariophyceae)

Light is an important parameter in algal culturing.In this work,the effects of different light qualities on growth of the marine diatom Chaetoceros gracilis are evaluated.The cells were cultured under light quantum flux density of 60μmol photons/(m2·s)with nine light qualities:LED red light(LR),LED blue light(LB),LED red plus LED blue light(LR+LB),LED white light(LW),fluorescent white light(FW),and combinations of LW and FW lights with increased proportions of red or blue light(FW+LR,FW+LB,LW+LR,and LW+LB).Blue light promoted the growth of C.gracilis largely.Three light qualities,FW+LR,LW+LR,and LR,resulted in the lowest growth rate.Both chlorophyll and carotenoids reached the highest level under LB and the lowest level under LR among monochromatic light sources;however,increasing of the proportion of blue or red light in the white light induced an increase of the chlorophyll and carotenoid concentrations.Light absorption ability of microalgae was critical for the growth of these organisms,as we observed a positive correlation between the extinction coefficient at different wavelengths and the specific growth rate.These findings are of importance to improve the culturing of this alga in bioreactors.

Chemical analysis,antimicrobial and anti-oxidative properties of Daucus gracilis essential oil and its mechanism of action

Objective:To evaluate the essential oils(EO) composition,antimicrobial and antioxidant power of a local plant,Daucus gracilis(D.gracilis).Methods:The aerial parts of D.gracilis were subjected to hydro distillation by a Clevenger apparatus type to obtain the EO which had been analyzed by gas chromatography and gas chromatography coupled with mass spectrometry,and screened for antimicrobial activity against five bacteria and three fungi by agar diffusion method.The mechanism of action of the EO was determined on the susceptible strains by both of time kill assay and lysis experience.The minimal inhibitory concentrations were determined by agar macrodilution and micro-dilution methods.Anti-oxidative properties of the EO were also studied by free diphenyl-2-picrylhydrazyl radical scavenging and reducing power techniques.Results:The EO yielded 0.68(v/w).The chemical analysis presented two dominant constituents which were the elemicin(35.3%) and the geranyl acetate(26.8%).D.gracilis EO inhibited the growth of Bacillus cereus and Proteus mirabilis significantly with minimal inhibitory concentrations of 17.15 μg/mL by the agar dilution method and57.05 μg/mL and 114.1 μg/mL,respectively by liquid micro-dilution.A remarkable decrease in a survival rate as well as in the absorbance in 260 nm was recorded,which suggested that the cytoplasm membrane was one of the targets of the EO.The EO showed,also,important anti-oxidative effects with an IC50 of 0.002 mg/mL and a dosedependent reducing power.Conclusions:D.gracilis EO showed potent antimicrobial and anti-oxidative activities and had acted on the cytoplasm membrane.These activities could be exploited in the food industry for food preservation.

ANALYSIS OF EVOLUTIONARY RELATIONSHIP BETWEEN ASTASIA LONGA AND EUGLENA GRACILIS BY USING RAPD TECHNIQUE AND CLADISTIC ANALYSIS

Although both Astasia longa and Euglena gracilis belong to different genera, they share many morphological characters except that A. longa has no chloroplast. In the 1940’s, on the basis of the finding that in darkness or upon addition of some chemicals, E. gracilis would fade reversibly or irreversibly, some scholars hypothesised that A. longa evolved from E. gracilis by losing chloroplast. The authors’ use of RAPD and cladistic analyses in a study on the evolutionary relationship between A .longa and E. gracilis showed that the A. longa ’s relationship with E. gracilis was closer than that with other green euglenoids. This proves the hypothesis that A. longa evolved from E. gracilis is reasonable. The results of this study suggest that saprophytic colorless euglenoids were transformed from green euglenoids by losing their choroplasts.

Application of biostimulants for vegetative propagation of endangered Abies gracilis

Abies gracilis Kom.(Pinaceae)is one of the rarest and endangered conifers in the Russian flora,which must be cultivated ex situ to ensure its survival.Cuttings of A.gracilis do not take root without biostimulants.We used a selection of biostimulants,concentrations,and conditions of their use to significantly increase Abies gracilis rooting,and to accelerate the production of planting material,and to reduce rooting time to one season.We tested 4 rooting systems:IBA,IBA with glucose and glycine,and original biostimulants(S-try and S-5).The original S-5 biostimulating system had the most balanced ratio of components.The number of rooted samples increased 2.7 times and the length of roots increased 1.8 time when using S-5 as compared to IBA.S-try and S-5-original biostimulant systems were synthesized and collected in 2011 and 2014,respectively,and were tested in St.Petersburg Forest Technical University.

Effect of NaNO_3 Concentrations on the Growth and Fatty Acid Compositions of Nitzschia closterium and Chaetoceros gracilis*

Fatty acid compositions of two strains of marine diatoms Nitzschia closterium ( MACC B222 ) and Chaetoceros gracilis ( MACC B13 ) have been examined. The microalgae have been grown at different initial NaNO3 concentrations ( 75, 375, 750, 1 125, 1 500, 1 875 mg/L ) and harvested at the late exponential phase. The results by one factor analysis of variance show that the NaNO3 concentrations have no significant influence on the relative growth rate of two strains of marine diatoms; the influence of NaNO3 concentrations on the fatty acids differs from species to species. The major fatty acids of two --diatom strains are 14:0, 16:0, 16:1n7 and 20:5n3 ( EPA ) , B13 also has high percentage -of 20:4n6 ( 6.0 ~ 9.1% ).

细薄膜壳绦虫[Hymenolepis gracilis(Zeder,1803)Cohn,1902]的发育史研究(多节绦虫亚纲:膜壳科)

细薄膜壳绦虫广布世界各地,常见寄生鸭和鹅。印度、日本、意大利、苏联及波兰等均有报告。国内林宇光(1959)首次描述本虫。国外报告多种剑水蚤、介虫等甲壳类可充当其中间宿主(Blanchard,1891;Mrazek,1891;Daday,1900;Linder,1921;Joyeux,1930等)。但国内有关本虫的生活史研究至今尚未见报告。作者进行本项研究,目的是观察研究本虫幼虫在中间宿主体内的发育规律,了解我省鸭。

Salvage irrigation-suction in gracilis muscle repair of complex rectovaginal and rectourethral fistulas

AIM:To evaluate the efficacy of gracilis muscle transposition and postoperative salvage irrigation-suction in the treatment of complex rectovaginal fistulas(RVFs)and rectourethral fistulas(RUFs).METHODS:Between May 2009 and March 2012,11female patients with complex RVFs and 8 male patients with RUFs were prospectively enrolled.Gracilis muscle transposition was undertaken in all patients and postoperative wound irrigation-suction was performed in patients with early leakage.Efficacy was assessed in terms of the success rate and surgical complications.SF-36 quality of life(QOL)scores and Wexner fecal incontinence scores were compared before and after surgery.RESULTS:The fistulas healed in 14 patients after gracilis muscle transposition;the initial healing rate was73.7%.Postoperative leakage occurred and continuous irrigation-suction of wounds was undertaken in 5patients:4 healed and 1 failed,and postoperative fecal diversions were performed for the patient whose treatment failed.At a median follow-up of 17 mo,the overall healing rate was 94.7%.Postoperative complications occurred in 4 cases.Significant improvement was observed in the quality outcomes framework scores(P<0.001)and Wexner fecal incontinence scores(P=0.002)after the successful healing of complex RVFs or RUFs.There was no significant difference in SF-36 QOL scores between the initial healing group and irrigationsuction-assisted healing group.CONCLUSION:Gracilis muscle transposition and postoperative salvage wound irrigation-suction gained a high success rate in the treatment of complex RVFs and RUFs.QOL and fecal incontinence were significantly improved after the successful healing of RVFs and RUFs.

A Rare Lobopodian,Antennacanthopodia gracilis n.gen.and sp.,from the Cambrian Chengjiang Lagersttte,Southwestern China,and Its Bearing on Basal Arthropod Phylogeny

Ancestral lobopodians,which diversified and flourished in the Cambrian seas,have long drawn much attention in that not only their living counterparts,onychophorans and tardigrades,but euarthropods(Chelicerata,Myriapoda,Crustacea,and Hexapoda) may have been deeply rooted in stem-group lobopodians.Antennacanthopodia gracilis new genus and species is described

Phenotypic plasticity and taxonomy of Cladophora gracilis(Griffiths)Kützing(Cladophorales,Chlorophyta)in the western Yellow Sea with the implication of its DNA barcode

Due to extensive morphological plasticity,the taxonomy of Cladophora species remains unclear.As one of the widely distributed species,C.gracilis was reported to hold many varieties,which make it difficult to identify the species.This study explored the morphology diversity of nine C.gracilis samples collected along the coast of western Yellow Sea.Some samples showed extremely varied characteristics,by which one cannot classify them correctly.Hence,18S rDNA and nuclear ribosomal DNA internal transcribed spacer regions(ITS)sequences were employed to delimit species.For 18S rDNA,sequence similarity ranged from 99.6%to 100%.For ITS region,the similarity ranged from 98.7%to 100%.Molecular data strongly suggested that the morphologically heterogeneous samples were actually the same species.Characteristics comparison of the samples revealed that the taxonomy criteria including branching pattern and density,thallus color,height and texture varied widely,influenced by environmental conditions and age of alga.Besides,cell dimensions,as the relatively stable criterion,also exhibited intraspecific variance.Successful application of 18S rDNA and ITS sequences indicated that molecular method can be a powerful assistant as DNA barcodes to traditional morphology taxonomy.

A new radiolarian species Clathrocorys gracilis from northern South China Sea

A new species, Clathrocorys gracilis nov. spec., of Tripocyrtidae (Radiolarians: Nassellaria) from surface water in northern South China Sea, is described in this paper. The new species has four radial beams arising from the cephalic base centre, each foot with cup-shaped structure and ramified bar in the proximal section (near cephalic base), and each wing with a large mesh in the middle, a medium mesh and a small mesh on each side respectively.

Occurrence and light response of residual plastid genes in a Euglena gracilis bleached mutant strain OflB2

Euglena gracilis is a unicellular green eukaryotic microalga that features characteristics of both plants and animals.The photosynthetic function of its chloroplast is easily lost under stress resulting in bleached mutants,while the physiological role of their residual plastid DNAs remains unclear.In this study,we obtained five bleached mutants by ofloxacin(Ofl)treatment,identified 12 residual plastid genes in five bleached mutants,and determined the mRNA levels in the wild type E.gracilis(WT)and one bleached mutant(OflB2)under dark and light stimulation conditions by quantitative reverse transcribed PCR(qRTPCR).Results show that the expression of all selected plastid genes in both WT and OflB2 mutant did not change significantly in darkness,while their responses to light stimulation were different.Under the light stimulation conditions,half of the genes did not change significantly,while most of the other genes were down-regulated in OflB2 mutant and up-regulated in WT.Therefore,the bleached mutant retains part of the plastid genome and the plastid relic is responsive to light.Our research will help to understand the functions of residual plastid DNA and evolution of chloroplasts.

Metazoan Parasites of the Mediterranean Garfish <i>Belone belone gracilis</i>(Teleostei: Belonidae) as a Tool for Stock Discrimination

The aim of the present study was to provide a current survey of metazoan parasites of the Mediterranean garfish Belone belone gracilis Lowe, 1839 off Tunisian coast and their potential use as biological tags for discriminate stocks. Parasitological analysis of 453 specimens of B. b. gracilis along the eastern Tunisian coast revealed the presence of ten species of metazoan parasites: one monogenean Axine belones Abildgaard, 1794;four digeneansLecithostaphylus retroflexus (Molin, 1859), Tergestia acanthocephala (Stossich, 1887) Stossich, 1899, Aponurus laguncula Looss, 1907 and Condylocotyla pilodora(metacercaria) Pearson et Prévot, 1985;one copepod Bomolochus bellonesBurmeister, 1835;two isopods Irona nana Schioedte et Meinert, 1884 andNerocila orbignyi (Guérin-Méneville, 1832);1 acanthocephalan Telosentis exiguus (Von Linstow, 1901) and one nematod Anisakid larvae. Discriminant analysis using parasites as biological tags, allowed identifying two stocks ofB. b. gracilis. Digenea L. retroflexus, A. laguncula and Anisakid larvae were the most important species in determining the position of sampled fishes from the central coast off Tunisia. Metacercaria C. pilodora characterized specimens from the Southern coast off Tunisia. These results were corroborated by comparing parameters of prevalence and mean abundance between zones. Discriminant analysis used for the separation of B. b. gracilis between seasons in both localities showed that a seasonal variation affected mainly specimens from the center suggesting seasonal move of fishes.

Life History of the Lenkoran Capoeta Capoeta Gracilis （Keyserling, 1981） in the Atrak River, Northern Iran

Within the wide distribution of Lenkoran in Iran, populations of the species inhabit variety of habitats. The authors hypothesized that each river may contribute to habitat-specific variation in life history of the fish. To test this, a total of 378 specimens of Capoeta capoeta gracilis caught in the Atrak river （northern Iran） from Dec. 2007 to Nov. 2008 were examined for life history attributes. The population has a 5-year life cycle. Weight-length relationship （WLR） was estimated as W = 0.0127TL28981 for males, W = 0.0083TL3998 for females and W = 0.0084TL3942 for the population, being allometric negative for males and positive for females and the population. The VBGF fit to back-calculated size at age data were： Lt = 22.11 （1-e-0.19（t＋135））, Lt = 25.37 （1-e-0.18（t＋125）） and Lt = 24.92 （1-e-018（1＋122）） for males, females and sexes combined respectively. Sex ratio was significant from the parity, females dominated. The reproductive season, evaluated from GSI, extended from Apr. to July, with the highest peak in May for males and in Apr. for females. The absolute fecundity ranged between 458-5,743 eggs with a mean of 1,375.06 eggs. Fecundity relative to total weight fluctuated from 14.90 to 132.58, with a mean value of 48.79 eggs·g-1. The diameter of oocytes ranged from 0.53 to 2.40 mm with a mean value of 1.46. The life history patterns of C. c. gracilis in the considered population imply that the many population characteristics of this species in the river differ markedly from those of other rivers of its range distribution in northern Iran. Probably, respond to environmental characteristics to improve fitness locally is the more suitable choice for differentiated life history strategies of the species in the river.

纤细角毛藻培养条件优化

采用正交实验的方法 ,对影响纤细角毛藻(Chaetocerosgracilis)生长的主要营养因素进行了优化 ,获得了以海水为基础的优化培养基配方 :NaHCO30.15g/L,Na2SiO3(9H2O0.20g/L,NaNO31.00g/L,KH2PO40.02g/L,VB12.7mg/L,VB121.5μg/L。实验表明 ,用该优化配方培养纤细角毛藻具有生长速度快、产量高的显著优势 ,为该微藻在光生物反应器中的进一步高密度培养提供了良好条件。

气候变暖与荒漠-草原过渡带植物动态响应灰色分析——以美国新墨西哥州Sevilleta生态过渡带为例

在当前全球气候变暖的形势下,地表生态系统表现出不同的响应。干旱半干旱地区的生态过渡带的生物反应更为敏感。美国新墨西哥州中部的荒漠草原生态过渡带是监测全球气候变化和人类活动对生物影响的重要区域之一。本文以Sevilleta荒漠草原生态过渡带为例,运用灰色系统分析方法,研究在当前全球气候变暖的条件下,1989～1998年10年间该生态过渡带的两种共存的植物优势种(Boutelouaeripoda)和(Boutelouagracilis)历年的种群密度、组合形式和变化趋势,分析引起这些变化的主要气候因子。结果表明,Sevilleta生态过渡带中来自荒漠草原的优势物种Boutelouaeripoda的密度有上升的趋势,来自大草原的优势物种Boutelouagracilis的密度有下降的趋势,它们的密度比大于1且有上升的趋势;在影响种群密度变化的降水、最高温度、最低温度、湿度的4个气候因子中,温度因子起着重要的作用。由此可以认为,随着气候的变暖,本区来自荒漠地区的优势植物种在荒漠草原群落过渡带中将逐渐处于强优势地位,生态过渡带将有可能被荒漠草原所替代。

半野生大豆起源及野生大豆稀有性状来源的形态学证据

针对国内外半野生大豆起源相关的五大争论焦点问题,结合本研究组近20年来对野生大豆和半野生大豆的形态学观察和研究,概述了我国半野生大豆天然杂交起源和野生大豆稀有性状来源的形态学证据。通过对我国半野生大豆的形态性状观察以及遗传标记分析鉴定,支持半野生大豆(G.gracilis Skvortsov)百粒重以3 g为界的观点,并发现百粒重在2.5~3.0 g之间时,其形态变异类型最丰富。通过捕捉野生和栽培大豆天然杂交当代种子及后代的形态性状分离调查,证实了半野生大豆起源于野生大豆和栽培大豆的天然杂交的论点。同时,研究结果表明,伴随天然杂交后的分离,一些稀有性状如白花、有色种皮(黄、绿、褐)、无泥膜、灰绒毛、绿子叶等是由栽培大豆逆向渗入到野生大豆中的。

叶绿体基因组的模式基因—光系统Ⅱ32kDa蛋白基因(psbA)的研究

从现有资料看,叶绿体基因组为一条裸露的双股螺旋的脱氧核糖核酸分子(cpDNA)其构象呈环状(单环、二聚体环或二聚体链环),大小在85～292kb,每个叶绿体中都含有22～900个拷贝,除豌豆,蚕豆和E.gracilis等少数植物外,大多数植物的cpDNA都含有一大小在10～76kb的主要编码rRNA基因的反向重复顺序(Kolodner et al.,1975;Bedbrook and Kolodner,1979;Whitfeld and Bo-

蛋黄果栽培管理和应用(2)

6病虫害防治6.1病害6.1.1蛋黄果拟盘多毛孢叶斑病6.1.1.1症状叶片上生圆形灰褐色病斑,中央灰白色至褐色,凹陷,大小3~4mm,病斑四周生宽的褐紫色环带,分生孢子盘成熟后现黑色小霉点。6.1.1.2病原细丽拟盘多毛孢[Pestalotiopsis gracilis（Kleb.）Steyaert]。6.1.1.3防治加强管理,提高抗病力。

两株硅藻筒柱藻和纤细角毛藻的油脂生产

通过气泡柱光反应器评价了两株硅藻筒柱藻(Cylindrotheca fusiformis)和纤细角毛藻(Chaetocerosgracilis)的生物量、油脂及甘油三脂的积累。结果发现,其生物量与油脂产率相当,脂肪酸组成方面,也均以C16:0和C16:1为主,但是筒柱藻的油脂组成以甘油三酯为主,纤细角毛藻的油脂以单酰甘油酯、磷脂和糖脂为主。通过培养条件的优化,发现相比于降低初始氮元素与硅元素,降低培养液盐度,能够获得更高的生物量、油脂以及甘油三脂产率。通过筒柱藻批次培养最高获得了0.36 g/(L.d)的甘油三脂产率,且甘三酯占收获干物质的50%以上,具有相当好的应用潜力。